1
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Wen Q, Chowdhury AI, Aydin B, Shekha M, Stenlid R, Forslund A, Bergsten P. Metformin restores prohormone processing enzymes and normalizes aberrations in secretion of proinsulin and insulin in palmitate-exposed human islets. Diabetes Obes Metab 2023; 25:3757-3765. [PMID: 37694762 DOI: 10.1111/dom.15270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/15/2023] [Accepted: 08/21/2023] [Indexed: 09/12/2023]
Abstract
AIM To elucidate how proinsulin synthesis and insulin was affected by metformin under conditions of nutrient overstimulation. MATERIALS AND METHODS Isolated human pancreatic islets from seven donors were cultured at 5.5 mmol/L glucose and 0.5 mmol/L palmitate for 12, 24 or 72 h. Metformin (25 μmol/L) was introduced after initial 12 h with palmitate. Proinsulin and insulin were measured. Expression of prohormone convertase 1/3 (PC1/3) and carboxypeptidase E (CPE), was determined by western blot. Adolescents with obesity, treated with metformin and with normal glucose tolerance (n = 5), prediabetes (n = 14), or type 2 diabetes (T2DM; n = 7) were included. Fasting proinsulin, insulin, glucose, 2-h glucose and glycated haemoglobin were measured. Proinsulin/insulin ratio (PI/I) was calculated. RESULTS In human islets, palmitate treatment for 12 and 24 h increased proinsulin and insulin proportionally. After 72 h, proinsulin but not insulin continued to increase which was coupled with reduced expression of PC1/3 and CPE. Metformin normalized expression of PC1/3 and CPE, and proinsulin and insulin secretion. In adolescents with obesity, before treatment, fasting proinsulin and insulin concentrations were higher in subjects with T2DM than with normal glucose tolerance. PI/I was reduced after metformin treatment in subjects with T2DM as well as in subjects with prediabetes, coupled with reduced 2-h glucose and glycated haemoglobin. CONCLUSIONS Metformin normalized proinsulin and insulin secretion after prolonged nutrient-overstimulation, coupled with normalization of the converting enzymes, in isolated islets. In adolescents with obesity, metformin treatment was associated with improved PI/I, which was coupled with improved glycaemic control.
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Affiliation(s)
- Quan Wen
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | | - Banu Aydin
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Mudhir Shekha
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Biology, College of Science, Salahaddin University, Erbil, Iraq
| | - Rasmus Stenlid
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
- Paediatric Obesity Clinic, Uppsala University Hospital, Uppsala, Sweden
| | - Anders Forslund
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
- Paediatric Obesity Clinic, Uppsala University Hospital, Uppsala, Sweden
| | - Peter Bergsten
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
- Paediatric Obesity Clinic, Uppsala University Hospital, Uppsala, Sweden
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2
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Liang C, Carrel D, Singh NK, Hiester LL, Fanget I, Kim H, Firestein BL. Carboxypeptidase E Independently Changes Microtubule Glutamylation, Dendritic Branching, and Neuronal Migration. ASN Neuro 2022; 14:17590914211062765. [PMID: 35014548 PMCID: PMC8755936 DOI: 10.1177/17590914211062765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neuronal migration and dendritogenesis are dependent on dynamic changes to the microtubule (MT) network. Among various factors that regulate MT dynamics and stability, post-translational modifications (PTMs) of MTs play a critical role in conferring specificity of regulatory protein binding to MTs. Thus, it is important to understand the regulation of PTMs during brain development as multiple developmental processes are dependent on MTs. In this study, we identified that carboxypeptidase E (CPE) changes tubulin polyglutamylation, a major PTM in the brain, and we examine the impact of CPE-mediated changes to polyglutamylation on cortical neuron migration and dendrite morphology. We show, for the first time, that overexpression of CPE increases the level of polyglutamylated α-tubulin while knockdown decreases the level of polyglutamylation. We also demonstrate that CPE-mediated changes to polyglutamylation are dependent on the CPE zinc-binding motif and that this motif is necessary for CPE action on p150Glued localization. However, overexpression of a CPE mutant that does not increase MT glutamylation mimics the effects of overexpression of wild type CPE on dendrite branching. Furthermore, although overexpression of wild type CPE does not alter cortical neuron migration, overexpression of the mutant may act in a dominant-negative manner as it decreases the number of neurons that reach the cortical plate (CP), as we previously reported for CPE knockdown. Overall, our data suggest that CPE changes MT glutamylation and redistribution of p150Glued and that this function of CPE is independent of its role in shaping dendrite development but plays a partial role in regulating cortical neuron migration.
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Affiliation(s)
- Chen Liang
- Department of Cell Biology and Neuroscience, Rutgers, 242612The State University of New Jersey, Piscataway, NJ, USA.,Molecular Biosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Damien Carrel
- SPPIN Laboratory, 555089Université de Paris, Centre National de la Recherche Scientifique UMR 8003, Paris, France
| | - Nisha K Singh
- Department of Cell Biology and Neuroscience, Rutgers, 242612The State University of New Jersey, Piscataway, NJ, USA.,Molecular Biosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Liam L Hiester
- Department of Cell Biology and Neuroscience, Rutgers, 242612The State University of New Jersey, Piscataway, NJ, USA
| | - Isabelle Fanget
- SPPIN Laboratory, 555089Université de Paris, Centre National de la Recherche Scientifique UMR 8003, Paris, France
| | - Hyuck Kim
- Department of Cell Biology and Neuroscience, Rutgers, 242612The State University of New Jersey, Piscataway, NJ, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, 242612The State University of New Jersey, Piscataway, NJ, USA
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3
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Abstract
Peptides derived from proopiomelanocortin (POMC) are well-established neuropeptides and peptide hormones that perform multiple functions, including regulation of body weight. In humans and some animals, these peptides include α- and β-melanocyte-stimulating hormone (MSH). In certain rodent species, no β-MSH is produced from POMC because of a change in the cleavage site. Enzymes that convert POMC into MSH include prohormone convertases (PCs), carboxypeptidases (CPs), and peptidyl-α-amidating monooxygenase (PAM). Humans and mice with inactivating mutations in either PC1/3 or carboxypeptidase E (CPE) are obese, which was assumed to result from defective processing of POMC into MSH. However, recent studies have shown that selective loss of either PC1/3 or CPE in POMC-expressing cells does not cause obesity. These findings suggest that defects in POMC processing cannot alone account for the obesity observed in global PC1/3 or CPE mutants. We propose that obesity in animals lacking PC1/3 or CPE activity depends, at least in part, on deficient processing of peptides in non-POMC-expressing cells either in the brain and/or the periphery. Genetic background may also contribute to the manifestation of obesity.
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Affiliation(s)
- Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
- Correspondence: I. Lindberg, PhD, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201, USA.
| | - Lloyd D Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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4
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Bosch E, Hebebrand M, Popp B, Penger T, Behring B, Cox H, Towner S, Kraus C, Wilson WG, Khan S, Krumbiegel M, Ekici AB, Uebe S, Trollmann R, Woelfle J, Reis A, Vasileiou G. BDV Syndrome: An Emerging Syndrome With Profound Obesity and Neurodevelopmental Delay Resembling Prader-Willi Syndrome. J Clin Endocrinol Metab 2021; 106:3413-3427. [PMID: 34383079 DOI: 10.1210/clinem/dgab592] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Indexed: 12/17/2022]
Abstract
CONTEXT CPE encodes carboxypeptidase E, an enzyme that converts proneuropeptides and propeptide hormones to bioactive forms. It is widely expressed in the endocrine and central nervous system. To date, 4 individuals from 2 families with core clinical features including morbid obesity, neurodevelopmental delay, and hypogonadotropic hypogonadism, harboring biallelic loss-of-function (LoF) CPE variants, have been reported. OBJECTIVE We describe 4 affected individuals from 3 unrelated consanguineous families, 2 siblings of Syrian, 1 of Egyptian, and 1 of Pakistani descent, all harboring novel homozygous CPE LoF variants. METHODS After excluding Prader-Willi syndrome (PWS), exome sequencing was performed in both Syrian siblings. The variants identified in the other 2 individuals were reported as research variants in a large-scale exome study and in the ClinVar database. Computational modeling of all possible missense alterations allowed assessing CPE tolerance to missense variants. RESULTS All affected individuals were severely obese with neurodevelopmental delay and other endocrine anomalies. Three individuals from 2 families shared the same CPE homozygous truncating variant c.361C > T, p.(Arg121*), while the fourth carried the c.994del, p.(Ser333Alafs*22) variant. Comparison of clinical features with previously described cases and standardization according to the Human Phenotype Ontology terms indicated a recognizable clinical phenotype, which we termed Blakemore-Durmaz-Vasileiou (BDV) syndrome. Computational analysis indicated high conservation of CPE domains and intolerance to missense changes. CONCLUSION Biallelic truncating CPE variants are associated with BDV syndrome, a clinically recognizable monogenic recessive syndrome with childhood-onset obesity, neurodevelopmental delay, hypogonadotropic hypogonadism, and hypothyroidism. BDV syndrome resembles PWS. Our findings suggest missense variants may also be clinically relevant.
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Affiliation(s)
- Elisabeth Bosch
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Moritz Hebebrand
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Bernt Popp
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 04103 Leipzig, Germany
| | - Theresa Penger
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Bettina Behring
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Helen Cox
- West Midlands Regional Clinical Genetics Unit, Birmingham Women's Hospital, Edgbaston, Birmingham B15 2TG, UK
| | - Shelley Towner
- Department of Pediatrics, Division of Genetics, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Cornelia Kraus
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - William G Wilson
- Department of Pediatrics, Division of Genetics, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Shagufta Khan
- West Midlands Regional Clinical Genetics Unit, Birmingham Women's Hospital, Edgbaston, Birmingham B15 2TG, UK
| | - Mandy Krumbiegel
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Arif B Ekici
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Steffen Uebe
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Regina Trollmann
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Joachim Woelfle
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Georgia Vasileiou
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
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5
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Kuo IY, Liu D, Lai WW, Wang YC, Loh YP. Carboxypeptidase E mRNA: Overexpression predicts recurrence and death in lung adenocarcinoma cancer patients. Cancer Biomark 2021; 33:369-377. [PMID: 34511486 DOI: 10.3233/cbm-210206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Effective biomarkers for prediction of recurrence of lung adenocarcinoma cancer (LADC) patients are needed to determine treatment strategies post-surgery to improve outcome. OBJECTIVE This study evaluates the efficacy of carboxypeptidase E (CPE) mRNA including its splice isoforms, CPE-ΔN, as a biomarker for predicting recurrence in adenocarcinoma patients. METHODS RNA was extracted from resected tumors from 86 patients with different stages of non-small cell LADC. cDNA was synthesized and qRT-PCR carried out to determine the copy numbers of CPE/CPE-ΔN mRNA. Patients were followed for 7 years post-tumor resection to determine recurrence and death. RESULTS ROC curve analysis showed the overall AUC for CPE/CPE-ΔN copy number was 0.563 in predicting recurrence and 0.563 in predicting death. Kaplan-Meier survival analysis showed statistical difference (p= 0.018), indicating that patients with high CPE/CPE-ΔN copy numbers had a shorter time of disease-free survival and also shorter time to death (p= 0.035). Subgroup analyses showed that association of disease-free survival time with CPE/CPE-ΔN copy number was stronger among stage I and II LADC patients (p= 0.047). CONCLUSIONS CPE/CPE-ΔN mRNA is a potentially useful biomarker for predicting recurrence and death in LADC patients, especially in identifying patients at high risk of recurrence at early stages I and II.
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Affiliation(s)
- I-Ying Kuo
- Institute of Basic Medical Sciences and Department of Pharmacology, National Cheng Kung University, Tainan, Taiwan
| | - Danping Liu
- Biostatistics and Bioinformatics Branch, Bethesda, MD, USA.,Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Wu-Wei Lai
- Department of Surgery, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Ching Wang
- Institute of Basic Medical Sciences and Department of Pharmacology, National Cheng Kung University, Tainan, Taiwan
| | - Y Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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6
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Li N, Teng SW, Zhao L, Li JR, Xu JL, Li N, Shuai JC, Chen ZY. Carboxypeptidase E Regulates Activity-Dependent TrkB Neuronal Surface Insertion and Hippocampal Memory. J Neurosci 2021; 41:6987-7002. [PMID: 34266900 PMCID: PMC8372023 DOI: 10.1523/jneurosci.0236-21.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/14/2021] [Accepted: 07/09/2021] [Indexed: 11/21/2022] Open
Abstract
Activity-dependent insertion of the tropomyosin-related kinase B (TrkB) receptor into the plasma membrane can explain, in part, the preferential effect of brain-derived neurotrophic factor (BDNF) on active neurons and synapses; however, the underlying molecular mechanisms remain obscure. Here, we report a novel function for carboxypeptidase E (CPE) in controlling chemical long-term potentiation stimuli-induced TrkB surface delivery in hippocampal neurons. Total internal reflection fluorescence assays and line plot assays showed that CPE facilitates TrkB transport from dendritic shafts to the plasma membrane. The Box2 domain in the juxtamembrane region of TrkB and the C terminus of CPE are critical for the activity-dependent plasma membrane insertion of TrkB. Moreover, the transactivator of transcription TAT-CPE452-466, which could block the association between CPE and TrkB, significantly inhibited neuronal activity-enhanced BDNF signaling and dendritic spine morphologic plasticity in cultured hippocampal neurons. Microinfusion of TAT-CPE452-466 into the dorsal hippocampus of male C57BL/6 mice inhibited the endogenous interaction between TrkB and CPE and diminished fear-conditioning-induced TrkB phosphorylation, which might lead to an impairment in hippocampal memory acquisition and consolidation but not retrieval. These results suggest that CPE modulates activity-induced TrkB surface insertion and hippocampal-dependent memory and sheds light on our understanding of the role of CPE in TrkB-dependent synaptic plasticity and memory modulation.SIGNIFICANCE STATEMENT It is well known that BDNF acts preferentially on active neurons; however, the underlying molecular mechanism is not fully understood. In this study, we found that the cytoplasmic tail of CPE could interact with TrkB and facilitate the neuronal activity-dependent movement of TrkB vesicles to the plasma membrane. Blocking the association between CPE and TrkB decreased fear-conditioning-induced TrkB phosphorylation and led to hippocampal memory deficits. These findings provide novel insights into the role of CPE in TrkB intracellular trafficking as well as in mediating BDNF/TrkB function in synaptic plasticity and hippocampal memory.
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Affiliation(s)
- Na Li
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | | | - Ling Zhao
- Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Jing-Rui Li
- College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, Shandong Normal University, Jinan 250014, China
| | - Jia-Ling Xu
- Institution of Traditional Chinese Medicine Innovation Research, Shandong University of Traditional Chinese Medicine, Jinan, 250355 China
| | - Na Li
- Departments of Anatomy and Neurobiology and
| | | | - Zhe-Yu Chen
- Departments of Anatomy and Neurobiology and
- Institute of Brain Science, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Institution of Traditional Chinese Medicine Innovation Research, Shandong University of Traditional Chinese Medicine, Jinan, 250355 China
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7
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Durmaz A, Aykut A, Atik T, Özen S, Ayyıldız Emecen D, Ata A, Işık E, Gökşen D, Çoğulu Ö, Özkınay F. A New Cause of Obesity Syndrome Associated with a Mutation in the Carboxypeptidase Gene Detected in Three Siblings with Obesity, Intellectual Disability and Hypogonadotropic Hypogonadism. J Clin Res Pediatr Endocrinol 2021; 13:52-60. [PMID: 32936766 PMCID: PMC7947731 DOI: 10.4274/jcrpe.galenos.2020.2020.0101] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Carboxypeptidase E (CPE) plays a critical role in the biosynthesis of peptide hormones and neuropeptides in the endocrine system and central nervous system. CPE knockout mice models exhibit disorders such as diabetes, hyperproinsulinaemia, low bone mineral density and neurodevelopmental disorders. Only one patient is described with morbid obesity, intellectual disability, abnormal glucose homeostasis and hypogonadotropic hypogonadism, which was associated with a homozygous frameshift deletion in CPE. METHODS Herein are described three siblings with obesity, intellectual disability and hypogonadotropic hypogonadism. Whole exome sequencing (WES) was performed in the index case. Candidate variants were prioritised and segregation of the variant, consistent with the phenotype of the index case, was assessed by Sanger sequencing in affected siblings and parents. RESULTS WES analysis revealed a homozygous nonsense c.405C>A (p.Y135*) mutation in CPE. Validation and segregation analysis confirmed the homozygous mutation in the index case and his affected siblings. The parents were phenotypically normal heterozygous mutation carriers. CONCLUSION This study provides additional evidence of the association between a homozygous nonsense mutation in CPE and a clinical phenotype consisting of obesity, intellectual disability and hypogonadotropic hypogonadism, which may be considered as a new monogenic obesity syndrome.
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Affiliation(s)
- Asude Durmaz
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey,* Address for Correspondence: Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey E-mail:
| | - Ayça Aykut
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey
| | - Tahir Atik
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Samim Özen
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Endocrinology, İzmir, Turkey
| | - Durdugül Ayyıldız Emecen
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Aysun Ata
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Endocrinology, İzmir, Turkey
| | - Esra Işık
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Damla Gökşen
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Endocrinology, İzmir, Turkey
| | - Özgür Çoğulu
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey,Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Ferda Özkınay
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey,Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
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Essawy A, Jo S, Beetch M, Lockridge A, Gustafson E, Alejandro EU. O-linked N-acetylglucosamine transferase (OGT) regulates pancreatic α-cell function in mice. J Biol Chem 2021; 296:100297. [PMID: 33460647 PMCID: PMC7949098 DOI: 10.1016/j.jbc.2021.100297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/05/2021] [Accepted: 01/12/2021] [Indexed: 01/06/2023] Open
Abstract
The nutrient sensor O-GlcNAc transferase (OGT) catalyzes posttranslational addition of O-GlcNAc onto target proteins, influencing signaling pathways in response to cellular nutrient levels. OGT is highly expressed in pancreatic glucagon-secreting cells (α-cells), which secrete glucagon in response to hypoglycemia. The objective of this study was to determine whether OGT is necessary for the regulation of α-cell mass and function in vivo. We utilized genetic manipulation to produce two α-cell specific OGT-knockout models: a constitutive glucagon-Cre (αOGTKO) and an inducible glucagon-Cre (i-αOGTKO), which effectively delete OGT in α-cells. Using approaches including immunoblotting, immunofluorescent imaging, and metabolic phenotyping in vivo, we provide the first insight on the role of O-GlcNAcylation in α-cell mass and function. αOGTKO mice demonstrated normal glucose tolerance and insulin sensitivity but displayed significantly lower glucagon levels during both fed and fasted states. αOGTKO mice exhibited significantly lower α-cell glucagon content and α-cell mass at 6 months of age. In fasting, αOGTKO mice showed impaired pyruvate stimulated gluconeogenesis in vivo and reduced glucagon secretion in vitro. i-αOGTKO mice showed similarly reduced blood glucagon levels, defective in vitro glucagon secretion, and normal α-cell mass. Interestingly, both αOGTKO and i-αOGTKO mice had no deficiency in maintaining blood glucose homeostasis under fed or fasting conditions, despite impairment in α-cell mass and function, and glucagon content. In conclusion, these studies provide a first look at the role of OGT signaling in the α-cell, its effect on α-cell mass, and its importance in regulating glucagon secretion in hypoglycemic conditions.
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Affiliation(s)
- Ahmad Essawy
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Seokwon Jo
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Megan Beetch
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Amber Lockridge
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Eric Gustafson
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Emilyn U Alejandro
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA.
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9
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Moon Y, Moon R, Roh H, Chang S, Lee S, Park H. HIF-1α-Dependent Induction of Carboxypeptidase A4 and Carboxypeptidase E in Hypoxic Human Adipose-Derived Stem Cells. Mol Cells 2020; 43:945-952. [PMID: 33203807 PMCID: PMC7700838 DOI: 10.14348/molcells.2020.0100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/22/2020] [Accepted: 10/29/2020] [Indexed: 12/29/2022] Open
Abstract
Hypoxia induces the expression of several genes through the activation of a master transcription factor, hypoxia-inducible factor (HIF)-1α. This study shows that hypoxia strongly induced the expression of two carboxypeptidases (CP), CPA4 and CPE, in an HIF-1α-dependent manner. The hypoxic induction of CPA4 and CPE gene was accompanied by the recruitment of HIF-1α and upregulation in the active histone modification, H3K4me3, at their promoter regions. The hypoxic responsiveness of CPA4 and CPE genes was observed in human adipocytes, human adipose-derived stem cells, and human primary fibroblasts but not mouse primary adipocyte progenitor cells. CPA4 and CPE have been identified as secreted exopeptidases that degrade and process other secreted proteins and matrix proteins. This finding suggests that hypoxia changes the microenvironment of the obese hypoxic adipose tissue by inducing the expression of not only adipokines but also peptidases such as CPA4 and CPE.
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Affiliation(s)
- Yunwon Moon
- Department of Life Science, University of Seoul, Seoul 02504, Korea
- Present address: Cell Therapy Research Center, GC LabCell, Yongin 16924, Korea
- These authors contributed equally to this work
| | - Ramhee Moon
- Department of Life Science, University of Seoul, Seoul 02504, Korea
- These authors contributed equally to this work
| | - Hyunsoo Roh
- Department of Life Science, University of Seoul, Seoul 02504, Korea
| | - Soojeong Chang
- Department of Life Science, University of Seoul, Seoul 02504, Korea
| | - Seongyeol Lee
- Department of Life Science, University of Seoul, Seoul 02504, Korea
| | - Hyunsung Park
- Department of Life Science, University of Seoul, Seoul 02504, Korea
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Liang C, Carrel D, Omelchenko A, Kim H, Patel A, Fanget I, Firestein BL. Cortical Neuron Migration and Dendrite Morphology are Regulated by Carboxypeptidase E. Cereb Cortex 2019; 29:2890-2903. [PMID: 29982499 PMCID: PMC6611459 DOI: 10.1093/cercor/bhy155] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 12/28/2022] Open
Abstract
Higher brain function relies on proper development of the cerebral cortex, including correct positioning of neurons and dendrite morphology. Disruptions in these processes may result in various neurocognitive disorders. Mutations in the CPE gene, which encodes carboxypeptidase E (CPE), have been linked to depression and intellectual disability. However, it remains unclear whether CPE is involved in early brain development and in turn contributes to the pathophysiology of neurocognitive disorders. Here, we investigate the effects of CPE knockdown on early brain development and explore the functional significance of the interaction between CPE and its binding partner p150Glued. We demonstrate that CPE is required for cortical neuron migration and dendrite arborization. Furthermore, we show that expression of CPE-C10 redistributes p150Glued from the centrosome and that disruption of CPE interaction with p150Glued leads to abnormal neuronal migration and dendrite morphology, suggesting that a complex between CPE and p150Glued is necessary for proper neurodevelopment.
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Affiliation(s)
- Chen Liang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
- Molecular Biosciences Graduate Program, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
| | - Damien Carrel
- Neurophotonics Laboratory, Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique UMR 8250, Paris, France
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
- Neuroscience Graduate Program, Rutgers, The State University of New Jersey, 683 Hoes Lane West, USA
| | - Hyuck Kim
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
| | - Aashini Patel
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
| | - Isabelle Fanget
- Neurophotonics Laboratory, Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique UMR 8250, Paris, France
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
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11
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Ji L, Wu HT, Qin XY, Lan R. Dissecting carboxypeptidase E: properties, functions and pathophysiological roles in disease. Endocr Connect 2017; 6:R18-R38. [PMID: 28348001 PMCID: PMC5434747 DOI: 10.1530/ec-17-0020] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 03/27/2017] [Indexed: 01/02/2023]
Abstract
Since discovery in 1982, carboxypeptidase E (CPE) has been shown to be involved in the biosynthesis of a wide range of neuropeptides and peptide hormones in endocrine tissues, and in the nervous system. This protein is produced from pro-CPE and exists in soluble and membrane forms. Membrane CPE mediates the targeting of prohormones to the regulated secretory pathway, while soluble CPE acts as an exopeptidase and cleaves C-terminal basic residues from peptide intermediates to generate bioactive peptides. CPE also participates in protein internalization, vesicle transport and regulation of signaling pathways. Therefore, in two types of CPE mutant mice, Cpefat/Cpefat and Cpe knockout, loss of normal CPE leads to a lot of disorders, including diabetes, hyperproinsulinemia, low bone mineral density and deficits in learning and memory. In addition, the potential roles of CPE and ΔN-CPE, an N-terminal truncated form, in tumorigenesis and diagnosis were also addressed. Herein, we focus on dissecting the pathophysiological roles of CPE in the endocrine and nervous systems, and related diseases.
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Affiliation(s)
- Lin Ji
- Department of Cell Biology & Medical GeneticsSchool of Medicine, Shenzhen University, Shenzhen, China
| | - Huan-Tong Wu
- Beijing Engineering Research Center of Food Environment and HealthCollege of Life & Environmental Sciences, Minzu University of China, Beijing, China
| | - Xiao-Yan Qin
- Beijing Engineering Research Center of Food Environment and HealthCollege of Life & Environmental Sciences, Minzu University of China, Beijing, China
| | - Rongfeng Lan
- Department of Cell Biology & Medical GeneticsSchool of Medicine, Shenzhen University, Shenzhen, China
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Mizutani A, Inoko H, Tanaka M. Carboxypeptidase E, Identified As a Direct Interactor of Growth Hormone, Is Important for Efficient Secretion of the Hormone. Mol Cells 2016; 39:756-761. [PMID: 27788574 PMCID: PMC5104884 DOI: 10.14348/molcells.2016.0183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/09/2016] [Accepted: 09/22/2016] [Indexed: 11/27/2022] Open
Abstract
We have identified 88 interactor candidates for human growth hormone (GH) by the yeast two-hybrid assay. Among those, we focused our efforts on carboxypeptidase E (CPE), which has been thought to play a key role in sorting prohormones, such as pro-opiomelanocortin (POMC), to regulated secretory vesicles. We found that CPE co-localizes with and interacts with GH in AtT20 pituitary cells. Downregulation of CPE led to decreased levels of GH secretion, consistent with involvement of CPE in GH sorting/secretion. Our binding assay in vitro with bacterially expressed proteins suggested that GH directly interacts with CPE but in a manner different from POMC.
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Affiliation(s)
- Akiko Mizutani
- Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193,
Japan
- Faculty of Health and Medical Science, Teikyo Heisei University, Higashi-Ikebukuro, Toshima, Tokyo 170-8445,
Japan
| | - Hidetoshi Inoko
- Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193,
Japan
| | - Masafumi Tanaka
- Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa 259-1193,
Japan
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Fan S, Li X, Li L, Wang L, Du Z, Yang Y, Zhao J, Li Y. Silencing of carboxypeptidase E inhibits cell proliferation, tumorigenicity, and metastasis of osteosarcoma cells. Onco Targets Ther 2016; 9:2795-803. [PMID: 27274275 PMCID: PMC4869623 DOI: 10.2147/ott.s98991] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Carboxypeptidase E (CPE), a prohormone processing enzyme, has been implicated in the progression of multiple malignancies. However, the biological role and molecular mechanisms of CPE in osteosarcoma remain elusive. In this study, we assessed the effects of CPE on cell proliferation, tumorigenicity, migration, and invasion in osteosarcoma. Our results showed that silencing of CPE significantly inhibited cell proliferation, caused cell cycle arrest at G0/G1 phase, decreased the expression levels of cell cycle protein, cyclin D1, and inhibited tumorigenicity in vivo. Additionally, CPE downregulation repressed the migratory and invasive capacities of osteosarcoma cells in vitro. Furthermore, overexpression of CPE-ΔN (a splice variant of CPE) enhanced the cell growth, migration, and invasion of osteosarcoma cells. It is possible that both CPE forms are involved in the tumorigenesis and development of osteosarcoma, and therefore CPE may provide a promising biological target for osteosarcoma therapy.
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Affiliation(s)
- Shuli Fan
- Department of Geriatrics, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Xu Li
- Department of Sports Medicine and Joint Surgery, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Leiming Li
- Department of Sports Medicine and Joint Surgery, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Liguo Wang
- Department of Sports Medicine and Joint Surgery, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Zhangzhen Du
- Department of Sports Medicine and Joint Surgery, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Yan Yang
- Department of Sports Medicine and Joint Surgery, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Jiansong Zhao
- Department of Orthopaedic Surgery, Shengjing Hospital of China Medical University, Shenyang, People's Republic of China
| | - Yan Li
- Department of Orthopaedic Surgery, Shengjing Hospital of China Medical University, Shenyang, People's Republic of China
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Kruchinina AD, Gengin MT. [Effect of reboxetine on activity of carboxypeptidase E in the nerve tissue of rats]. Biomed Khim 2015; 61:657-60. [PMID: 26539877 DOI: 10.18097/pbmc20156105657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Depression is one of the most common mental disorders, but its etiology is not completely understood. It is assumed that peptidergic system components are involved in the formation of this pathology. Neuropeptides play an important role in the regulation of mental and emotional states. Сarboxypeptidase E is a key enzyme of peptide processing; it regulates neuropeptide levels in the various structures of the nervous system. We have studied effects of a single dose of reboxetine on the activity of carboxypeptidase E in various brain regions and the adrenal glands of rats. The reboxetine injection decreased carboxypeptidase E activity in the pituitary gland (12 h after injection), in the pituitary gland, the quadrigeminal bodies, the medulla oblongata, the hypothalamus, the hippocampus and the amygdala (24 h after injection), in the pituitary gland and striatum (72 h after injection). The enzyme activity in adrenal glands remained basically unchanged. Apparently, the decrease of carboxypeptidase E activity may influence the level of regulatory peptides involved in the pathogenesis of depression.
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Hiramoto K, Kobayashi H, Sekiyama A, F Sato E, Tsuruta D, Ishii M. Mild exercise suppresses exacerbation of dermatitis by increasing cleavage of the β-endorphin from proopiomelanocortin in NC/Nga mice. J Clin Biochem Nutr 2013. [PMID: 23341699 DOI: 10.3164/jcbn.12.51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigated the mechanism by which the strength and weakness of exercise stress affects the skin symptoms of atopic dermatitis (AD). Specific pathogen-free (SPF) and conventional NC/Nga mice were used. Conventional mice, but not the SPF, spontaneously develop dermal symptoms similar to that of patients with AD. There were two types of stress, mild (20 m/min for 60 min) or strong exercise (25 m/min for 90 min), using a treadmill four times per day. The symptom of the conventional group were strongly exacerbated by strong exercise but ameliorated by mild exercise. The plasma concentrations of α-melanocyte stimulating hormone (α-MSH) and the expression of melanocortin receptor-1 in skin elevated after strong exercise but decreased after mild exercise. The plasma levels of β-endorphin and the expression of µ-opioid receptor in skin were increased by mild exercise. In addition, the expression of prohormone convertase (PC) 1/3, PC2 and carboxypeptidase E (CPE) in pituitary gland were higher in the conventional group than in the SPF group. The level of PC2 was suppressed by mild exercise in the conventional groups, and elevated further by strong exercise. The level of PC1/3 becomes higher with the increase of the exercise load. On the other hand, the expression of the CPE was further increase by mild exercise but suppressed by strong exercise. These observations suggested that exercise-induced stress significantly affect the symptoms of AD in a pivotal manner depending on the levels of α-MSH and β-endorphin, and the expression of pituitary PC2 and CPE.
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Affiliation(s)
- Keiichi Hiramoto
- Department of Dermatology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno, Osaka 545-8585, Japan ; Brain Science Institute, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno, Osaka 545-8585, Japan
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Hiramoto K, Kobayashi H, Sekiyama A, F Sato E, Tsuruta D, Ishii M. Mild exercise suppresses exacerbation of dermatitis by increasing cleavage of the β-endorphin from proopiomelanocortin in NC/Nga mice. J Clin Biochem Nutr 2012; 52:58-63. [PMID: 23341699 PMCID: PMC3541420 DOI: 10.3164/jcbn.12-51] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 09/17/2012] [Indexed: 12/16/2022] Open
Abstract
This study investigated the mechanism by which the strength and weakness of exercise stress affects the skin symptoms of atopic dermatitis (AD). Specific pathogen-free (SPF) and conventional NC/Nga mice were used. Conventional mice, but not the SPF, spontaneously develop dermal symptoms similar to that of patients with AD. There were two types of stress, mild (20 m/min for 60 min) or strong exercise (25 m/min for 90 min), using a treadmill four times per day. The symptom of the conventional group were strongly exacerbated by strong exercise but ameliorated by mild exercise. The plasma concentrations of α-melanocyte stimulating hormone (α-MSH) and the expression of melanocortin receptor-1 in skin elevated after strong exercise but decreased after mild exercise. The plasma levels of β-endorphin and the expression of µ-opioid receptor in skin were increased by mild exercise. In addition, the expression of prohormone convertase (PC) 1/3, PC2 and carboxypeptidase E (CPE) in pituitary gland were higher in the conventional group than in the SPF group. The level of PC2 was suppressed by mild exercise in the conventional groups, and elevated further by strong exercise. The level of PC1/3 becomes higher with the increase of the exercise load. On the other hand, the expression of the CPE was further increase by mild exercise but suppressed by strong exercise. These observations suggested that exercise-induced stress significantly affect the symptoms of AD in a pivotal manner depending on the levels of α-MSH and β-endorphin, and the expression of pituitary PC2 and CPE.
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Affiliation(s)
- Keiichi Hiramoto
- Department of Dermatology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno, Osaka 545-8585, Japan ; Brain Science Institute, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno, Osaka 545-8585, Japan
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